OBJECTIVE: To investigate the behavioral changes and monoamine neurotransmitter levels in a rat model of chronic unpredictable mild stress (CUMS)-induced depression and explore the potential effects of Vitamin B METHODS: A total of 72 Sprague-Dawley (SD) rats were randomly assigned to 3 groups, a control group, a CUMS group (subjected to three weeks of CUMS), and a CUMS + VitB RESULTS: Starting from week 5, rats in the CUMS group exhibited lower average body mass compared to the control group, while the CUMS + VitB CONCLUSION: In CUMS rats, the levels of monoamine neurotransmitters (5-HT, NE, and DA) in the cerebral cortex of the brain are decreased, accompanied by a decrease in neuronal cells, which results in anxiety- and depression-like behaviors. VitB